Tool for a vacuum cleaner

ABSTRACT

A vacuum cleaner flexible duct. The flexible duct includes a helical frame and a helical strip. The helical frame includes a plurality of loops arranged about a helical axis and is formed of a rigid material. The helical strip is provided on the helical frame to seal the flexible duct and is formed of pliable material and. At least one loop of the helical frame has one or more projections that extend towards an adjacent loop. The projections limit the flexing of the flexible duct in a direction normal to the helical axis.

REFERENCE TO RELATED APPLICATIONS

This application claims the priority of United Kingdom Application No.1612134.5, filed Jul. 13, 2016, the entire contents of which areincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a flexible duct for a vacuum cleaner.More specifically, the present invention relates to a flexible duct fora vacuum cleaner tool.

BACKGROUND OF THE INVENTION

FIGS. 1 and 2 are examples of flexible crevice tools 100, 200 that canbe used with a vacuum cleaner. The tools 100, 200 are intended to reachinto and clean crevices or gaps to be cleaned. Both of the tools shownin FIGS. 1 and 2 comprise a flexible duct 300 formed from a pliablecasing material 400 which is reinforced by a rigid frame 500. Anysteering force applied to the tool 100, 200 when it is in a crevicecauses the pliable casing material 400 to bend. The rigid frame 500 isused to improve the control and steering of the tool in a desireddirection, and to prevent the flexible duct 300 from folding over itselfor kinking. Folding or kinking of the duct should be prevented as thiscan restrict the flow of fluid drawn through the tool 100, 200, and mayalso cause damage to the flexible duct 300.

The two examples of crevice tools 100, 200 employ two different types ofrigid frames 500 in order to improve control and steering of the tool,and to prevent folding or kinking of the duct. A problem with the tool100 shown in FIG. 1 is that the use of a rigid central spine 600completely restricts the duct from flexing in a particular direction,i.e. the direction of the spine 600. This could be problematic, forexample, if a crevice to be cleaned is an irregular shape since the toolmay suffer from reduced manoeuvrability in the crevice.

The tool 200 shown in FIG. 2 introduces a helical shape frame 700 toimprove the flex of the duct. The pliable casing material 400 is free tobend and flex in all directions. The range of flexibility of the duct300 and its manoeuvrability in the crevice is therefore improved.However, there is still a risk that the pliable casing material 400could still fold or kink if the regular rotations of the helical frame700 are spaced too far apart or if the material used for the helicalframe 700 is too flexible. The duct frames 500 used in the prior arttools 100, 200 therefore present a compromise between the range offlexibility of the duct 300 and the prevention of folding or kinking ofthe duct 300.

SUMMARY OF THE INVENTION

In a first aspect, the present invention provides a vacuum cleaner toolcomprising a flexible duct, the flexible duct comprising a helical framecomprising a plurality of loops arranged about a helical axis and beingformed of a rigid material, and a helical strip provided on the loops toseal the frame and being formed of pliable materia, wherein at least oneloop has one or more projections that extend towards an adjacent loop soas to limit flexing of the flexible duct in a direction normal to thehelical axis.

By providing a projection on at least one of the loops of the helicalframe, the degree of movement of the flexible duct in directions normalto the helical axis is reduced without being overly constrained. Thisprovides the user with more control of the flexible duct in a desireddirection of steering, e.g. left/right direction instead of the ductflexing in an up/down direction. The risk of the user losing control andcausing the duct to fold or kink is also reduced since the projectionson a loop restrict the amount of movement of the duct in an undesireddirection. Consequently, this enables the duct to maintain a high degreeof flexibility and manoeuvrability, whilst also reducing the risk of theduct folding or kinking. The restriction of movement also has theadditional benefit of reducing the risk of damage caused to the flexibleduct by preventing over-flexing in a particular direction.

In terms of the flexing movement, the duct can be said to flex in aleft-right direction and in an up-down direction normal to the helicalaxis. The projections on the loops can be spaced or positioned such thatthey limit the overall range of movement of the duct in both theleft-right direction and the up-down direction. Conversely, they can bearranged so that they restrict the range of movement of the ductpredominantly in one direction normal to the helical axis (i.e. eitherleft/right or up/down), relative to the range of movement of the tool inthe other direction.

The cross section of the flexible duct may be a general rectangularshape, comprising two longer side surfaces connected by shorter top andbottom surfaces. The general rectangular shape of the flexible ductallows for a narrow profile crevice tool that can fit into most gaps andcrevices. The requirement of a general rectangular shape does notpreclude the curving or shaping of the sides of the rectangular duct foraesthetic or ergonomic purposes.

The projections on the loops may be aligned along the top surface and/orthe bottom surface of the flexible duct to limit the movement of theflexible duct in only one direction that is normal to the helical axis,i.e. an up/down direction. By limiting the movement of the flexible ductin a single direction the movement of the flexible duct is lessrestricted in the other directions normal to the helical axis. Byproviding the projections along one of the top or bottom surface themanoeuvrability of the duct can be improved. In addition, the amount ofmaterial used and the complexity of the part can be reduced whilst stillproviding a reasonable compromise between duct flexibility and theprevention of folding of the duct. The projections on the loops howevercan be provided on both the top surface and the bottom surface of theflexible duct. By having projections on the top and the bottom surfacesof the duct the user's control of the duct is improved and the risk ofthe duct folding or kinking and/or causing damage to itself can befurther reduced. For example, if the tool is used to clean a regularlyshaped gap or crevice, some force would be applied in an up or downdirection relative to the helical axis as the tool is pressed into thefloor of the crevice. It is therefore advantageous to reinforce the ductin this direction to prevent miss-steering of the duct and also foldingor damage to the tool.

The helical strip may have indents provided on the side surfaces of theflexible duct. The indents allow for improved flexibility of the ductand also provide a crease for the duct to fold into as it flexes.

Each loop may comprise a central band with at least one wing, thehelical strip being secured to the at least one wing such that theexterior surface of the helical strip is flush with the exterior and/orinterior surface of the central band. The helical strip is used to sealthe space between the rigid frame loops and may be in the form of asingle piece of material (such as a ribbon or bandage), or a series ofinterlinked bands that together provide a sealed duct. In other words,the helical strip is used to link the loops of the helical frame. Thehelical strip may be overmoulded or bonded onto the helical frame. Thehelical strip also can be provided only between the loops of the helicalframe, compared to a full sheath that covers both the frame and thespace between the loops of a frame.

The pliable sheaths that are used in the prior art examples are placedover the tool flexible duct to conceal the frame. In contrast to thesesheaths, using a single piece of helical strip material means that lessmaterial can be used to make a sealed duct. In addition, the helicalstrip between the loops can be formed so that it is flush with thecentral band of each loop. This is in contrast to fitting a sheath overthe frame and increasing the profile of the tool. Thus, the profile ofthe tool can be reduced so that it can fit into narrower gaps andcrevices without comprising manoeuvrability and the ability to controlthe tool. Although at least part of the helical frame may be uncovered(i.e. the central band of each loop may appear exposed), the helicalstrip can be used to cover other parts of the loops. For instance, thewings and the projections on the loops can be concealed by the helicalstrip. Furthermore, having a duct with a smooth internal surface reducesthe amount of losses through turbulence as the airflow is drawn throughthe duct.

The tool of the present invention may be a telescopic tool comprising afirst and second conduit; the first conduit has a narrower profile thanthe second conduit, the second conduit surrounds the first conduit suchthat the first conduit slides in and out of the second conduit allowingfor extension of the tool, and the flexible duct forms part of the firstconduit. The use of the flexible duct on a telescopic tool allows for alonger tool that can be placed into gaps or crevices to be cleaned.Furthermore, the provision of a rigid conduit together with a conduithaving the flexible duct improves the handling and manoeuvrability ofthe tool since the user can hold onto the rigid conduit and steer to thetool.

In a second aspect, the present invention provides a vacuum cleaner ductcomprising a helical frame comprising a plurality of loops arrangedabout a helical axis and being formed of a rigid material, and a helicalstrip provided on the loops to seal the frame and being formed ofpliable material, wherein at least one loop has one or more projectionsthat extend towards an adjacent loop so as to limit flexing of the ductin a direction normal to the helical axis.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the present invention may be more readily understood, anembodiment of the invention will now be described, by way of example,with reference to the accompanying drawings, in which:

FIG. 1 is a tool forming part of the prior art;

FIG. 2 is another tool forming part of the prior art;

FIG. 3 is a perspective view of a tool comprising a flexible duct of thepresent invention;

FIG. 4 is a perspective view of the flexible duct of the presentinvention;

FIG. 5 is an exploded view of the flexible duct of the presentinvention, with an insert showing the details of the frame;

FIG. 6 is a top view of the tool of FIG. 3; and

FIG. 7 is a plan view of the tool of FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 3 shows a tool 1 comprising a first conduit 2, a second conduit 3,a first connector 4 and a second connector 5. The first conduit 2 has anarrower profile than the second conduit 3, and the second conduit 3surrounds the first conduit 2 such that the first conduit 2 slides inand out of the second conduit 3, allowing for extension of the tool 1.When the tool 1 is extended, the first conduit 2 is revealed from thesecond conduit 3. Such a tool 1 can be said to be telescopic.

The first conduit 2 is connected at one end to the second conduit 3 andat the opposite end to the first connector 4. The second conduit 3 isconnected to the second connector 5. The second connecter 5 is locatedat the end opposite to where the first conduit 2 connects to the secondconduit 3. The first connector 4 can be used for connecting a nozzle orcleaner head to the end of the tool 1. Alternatively, the firstconnector 4 can act as an inlet for the tool without the need for anozzle or cleaner head attachment. The second connector 5 is used toconnect the tool 1 to a wand or hose that further connects to a vacuumcleaner.

The tool 1 further comprises locking means 6 for locking the conduits2,3 of the tool 1 out at maximum extension (as shown in FIG. 3) and alsofor locking the first conduit 2 in a retracted position when it islocated within the second conduit 3.

The first conduit 2 comprises a flexible portion or duct 7 and rigidportions 8 at either end of the flexible duct 7. The flexible duct 7 isshown in more detail in FIGS. 4 to 7 and comprises a helical frame 9 anda helical strip 10. The flexible duct 7 has a generally rectangularshape cross section, with two longer side surfaces 11,12 (best shown inFIG. 6) and two shorter top and bottom surfaces 13,14 (best shown inFIG. 7). The flexible duct 7 can flex in directions normal to thehelical axis 15. For example, the flexible duct 7 is free to flex in aleft to right direction, and also in an up and down direction, as shownin FIGS. 6 and 7 respectively. Dashed lines are used to illustrate thegeneral degree of movement of the flexible duct 7 in directions normalto the helical axis 15.

The helical frame 9 is formed of a single piece of rigid material andcomprises a plurality of loops 16 that are arranged around the helicalaxis 15. The loops 16 are spaced at regular intervals along the helicalaxis 15 with a space between each loop 16. The profile of each loop 16is shown in more detail in FIG. 5. Each loop 16 comprises a central band17 flanked by wings 18, 19 on either side of the band 17, the band 17being of greater thickness than the wings 18,19. That is to say that theheight of the wings 18,19 is less than the height of the central band 17in a direction normal to the helical axis 15. Each wing 18,19 extendsall the way around the central band 17 in a direction parallel with thehelical axis 15 and is provided with anchors 20 which are used as keyingfeatures during the manufacturing process of the tool 1. One wing 19 isprovided with two projections 21 that extend towards an adjacent loop16. The projections 21 extend in a direction that is parallel to thehelical axis 15. The projections 21 are positioned on the top and bottomof the wing 19 (best shown in FIG. 5). The projections 21 act torestrict the movement of the flexible portion 7 in the up and downdirection relative to the movement of the flexible portion 7 in the leftto right direction.

The helical strip 10 is formed of a single piece of a pliable materialin the form of a tape, bandage or ribbon. The helical strip 10 extendsalong the helical axis 15 and around part of the helical frame 9.Specifically, the helical strip 10 is either overmoulded onto or bondedto the helical frame 9 such that the strip 10 fills the space betweeneach of the loops 16, providing a continuous coupling between the loops16 of the frame. The helical strip 10 seals the spaces in the helicalframe 9 to provide a duct for fluid to be drawn through. Furthermore,the helical strip 10 is provided between the loops 16 only on the wings18,19, such that the exterior of the helical strip 10 is flush with theexterior of the central band 17. As shown in FIG. 4, the central band 17of each loop 16 is exposed along the length of the duct 7. Since thehelical strip 10 is provided in the space between the loops 16 and flushwith the loops 16 the overall exterior profile of the flexible duct 7 isreduced.

The helical strip 10 is able to flex and stretch, allowing the flexibleportion 7 to bend or twist from a straight position and return back toits original shape. The helical strip 10 has indents 22 provided on theside surfaces 11, 12 of the duct 7. The indents 22 improve theflexibility of the duct 7 in two ways. Firstly, the indents 22 reducethe stiffness of the helical strip 10 on a side surface 11, 12 thatlengthens during a flexing movement (that is to say, the side surface11, 12 on the outside of the bend of the flexible duct portion 7).Secondly, the indents 22 allow for the material of the helical strip 10to crease and fold more readily on a side surface 11, 12 that contractsduring a flexing movement (that is to say, on the side surface 11, 12 onthe inside of the bend of the flexible duct portion 7).

The anchors 20 provided on the wings 18, 19 of each loop 16 of the frame9 act as keying features as the strip 10 is overmoulded onto the frame9. During manufacture, the pliable material flows over the wings 18, 19and into or onto the anchors 20. The anchors 20 are holes that areshaped so that the helical strip 10 is secured onto the frame 9 once thepliable material has cured. The pliable material is only provided on thewings 18,19 such that, once cured, the exterior surface of the helicalstrip 10 is flush with the exterior of the central band 17. In addition,a mould insert can be placed inside the flexible portion 7 of the firstconduit 2 and against the inside surface of the loops 16 such that thepliable material flows and cures against the mould insert. The mouldinsert is then removed after curing to leave behind a smooth interiorsurface of the duct 7 as the helical strip 10 is cured flush with theinterior profile of the loops 16.

During use, the tool 1 is extended so that the first conduit 2 isexposed as it slides outs of the second conduit 3. The travel of thefirst conduit 2 is locked when the tool 1 is in an extended position (asshown in FIG. 3). The profile of the tool 1 is such that at least thefirst conduit 2 can be placed into a gap or crevice. The user canmanoeuvre the tool 1 by holding either the second conduit 3, or byholding an extension wand or handle connected via the second connector5.

As the tool 1 is manoeuvred into a crevice, the flexible duct 7 of thefirst conduit 2 can bend or flex against the walls or floor of thecrevice. The user will naturally force the tool 1 against thesurface/floor of the crevice to be cleaned. As the force is applied, theflexible duct 7 will flex in an up/down and/or left/right direction. Asthe duct 7 bends or flexes in the up down direction, the projections 21limit the range of movement of the helical frame 9. This improves thecontrol of the tool 1 and gives the user the ability to steer the tool 1in a crevice without the duct 7 flexing in an unwanted direction (i.e.up/down direction). In addition, prevents the flexing of the duct 7beyond a point where damage or kinking would occur. Thus, although themaximum range in movement in the up and down direction is decreased, theduct 7 is protected against folding or kinking, and also reinforced toprevent any damage to the tool 1.

The movement of the flexible duct 7 in the left and right direction isimproved by the indents 21 that are provided on the side surfaces of thehelical strip 10. In use, the indents 21 provide improved flexibility,in that they are able to stretch more easily than the rest of thehelical strip 10 since less material is present. In addition, theindents 21 provide a crease or fold for the helical strip 10 to bendinto when flexing the duct 7. Thus, the steering of the tool 1 in aleft/right direction is easier relative to steering in an up/downdirection.

Although the flexible duct 7 is shown as part of a tool 1 for a vacuumcleaner, it will be appreciated that such a duct could be used on otherparts of the vacuum cleaner, such as a suitable replacement for a hose,or a tube, or a conduit connecting parts of a vacuum cleaner.

1. A vacuum cleaner tool comprising a flexible duct, the flexible ductcomprising: a helical frame comprising a plurality of loops arrangedabout a helical axis and being formed of a rigid material; and a helicalstrip provided on the loops to seal the frame and being formed ofpliable material; wherein at least one loop has one or more projectionsthat extend towards an adjacent loop so as to limit flexing of theflexible duct in a direction normal to the helical axis.
 2. The vacuumcleaner tool of claim 1, wherein a cross section of the flexible duct isa rectangular shape, comprising two longer side surfaces connected byshorter top and bottom surfaces.
 3. The vacuum cleaner tool of claim 2,wherein the projections located on the loop are provided along at leastone of the top surface and the bottom surface of the loop to limitmovement of the flexible duct in at least one of an up and a downdirection only.
 4. The vacuum cleaner tool of claim 3, wherein theprojections located on the loop are provided on both the top surface andthe bottom surface of the loop.
 5. The vacuum cleaner tool of claim 2,wherein the helical strip has indents provided on the side surfaces ofthe flexible duct.
 6. The vacuum cleaner tool of claim 1, wherein eachloop comprises a central band with at least one wing, the helical stripis secured to the at least one wing such that the exterior surface ofthe helical strip is flush with at least one of an exterior and aninterior surface of the central band.
 7. The vacuum cleaner tool ofclaim 1, wherein the tool is a telescopic tool comprising a firstconduit and a second conduit; the first conduit has a narrower profilethan the second conduit, the second conduit surrounds the first conduitsuch that the first conduit slides in and out of the second conduitallowing for extension of the tool, and the flexible duct forms part ofthe first conduit.
 8. A vacuum cleaner duct comprising: a helical framecomprising a plurality of loops arranged about a helical axis and beingformed of a rigid material; and a helical strip provided on the loops toseal the frame and being formed of pliable material; wherein at leastone loop has one or more projections that extend towards an adjacentloop so as to limit flexing of the duct in a direction normal to thehelical axis.
 9. The vacuum cleaner duct of claim 8, wherein a crosssection of the flexible duct is a rectangular shape, comprising twolonger side surfaces connected by shorter top and bottom surfaces. 10.The vacuum cleaner duct of claim 9, wherein the projections located onthe loop are provided along at least one of the top surface and thebottom surface of the loop to limit movement of the duct in at least oneof an up and a down direction only.
 11. The vacuum cleaner duct of claim10, wherein the projections located on the loop are provided on both thetop surface and the bottom surface of the loop.
 12. The vacuum cleanerduct of claim 8, wherein the helical strip has indents provided on theside surfaces of the duct.
 13. The vacuum cleaner tool of claim 8,wherein each loop comprises a central band with at least one wing, thehelical strip is provided over the at least one wing such that theexterior surface of the helical strip is flush with at least one of anexterior and an interior surface of the central band.